Install this version:
emerge -a =dev-java/xsom-20140925-r1
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =dev-java/xsom-20140925-r1
Or alternatively:
emerge --autounmask-write -a =dev-java/xsom-20140925-r1
# Copyright 1999-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=7
JAVA_PKG_IUSE="doc source"
inherit java-pkg-2 java-pkg-simple
DESCRIPTION="A Java library that allows for easy parsing and inspection of XML schema docs"
HOMEPAGE="https://xsom.dev.java.net/"
SRC_URI="https://repo1.maven.org/maven2/com/sun/${PN}/${PN}/${PV}/${P}-sources.jar -> ${P}.jar"
KEYWORDS="~amd64 ~x86"
SLOT="0"
LICENSE="CDDL"
IUSE=""
CP_DEPEND="
dev-java/relaxng-datatype:0
"
DEPEND="
>=virtual/jdk-1.8:*
${CP_DEPEND}
"
RDEPEND="
>=virtual/jre-1.8:*
${CP_DEPEND}
"
>=virtual/jdk-1.8:* dev-java/relaxng-datatype:0
>=virtual/jre-1.8:* dev-java/relaxng-datatype:0